1. Field of the Invention
The present invention is related to a fluorescence material applied to light emitting diode (LED) devices, and more particularly, to a structure of a fluorescence material.
2. Description of the Prior Art
It is an important objective for the illumination source technology field with actively researching and developing in this century to utilize LED devices for producing white light that is similar to the light color distribution of sunlight in order to substantially replace conventional white light illumination devices, such as fluorescent lamps. Currently, most of global package technology researchers of white light LED with single chip have working for develop blue light LED chips with wavelength of 440-460 nanometers (nm) and yttrium aluminum garnet (YAG) fluorescence powder, which can be excited by the blue light LED chip, for being mixed and packaged to produce white light. There is no definite operation method standard of packaging fluorescence powders in a white light LED package.
Furthermore, the technology of white light package has been widely discussed and researched. Therefore, how to improve the extraction efficiency of light becomes an important issue. For example, surface-roughening, arrangement of photonic crystal, and design of package structure are verified methods for effectively raising the extraction efficiency of light. In addition, the structure disposition of fluorescence powder layer has been valued gradually.
However, most of the researches have been emphasized on design of the whole structure of LED devices, or the coating disposition or structure variation of the fluorescence powder layer, and the research or discussion of fluorescence powder particle itself is very seldom.
In fact, the surface structure and size of the fluorescence powder particle do influence in the extraction efficiency of light. Therefore, to provide a fluorescence material for improving the extraction efficiency of light through the design of the particle structure of fluorescence material is essential for the manufacturers.